Method for evaluating contact pin integrity of electronic components having multiple contact pins

ABSTRACT

An apparatus and method for evaluating the integrity of each contact pin of an electronic component having multiple contact pins. In one embodiment, the apparatus includes a test device and a measuring instrument. The test device comprises a component fixture configured to hold an electronic component under test and opposing contact plates for establishing electrical communication between the contact pins of the electronic component and the measuring instrument. The test device may include separate linear positioners associated with each opposing contact plate configured to move the contact plates relative to the component fixture and electronic component under test. The measuring instrument measures at least one electrical characteristic of a pin contact. In another embodiment, the apparatus further includes a system controller in communication with the measuring instrument and configured to control functioning of the measuring instrument.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of application Ser. No. 09/448,882,filed Nov. 24, 1999, now U.S. Pat. 6,504,378, issued Jan. 7, 2003.

BACKGROUND OF THE INVENTION

Field of the Invention: The present invention relates generally to themanufacturing and testing of electronic components. Specifically, thepresent invention relates to a method and apparatus for evaluating theelectrical characteristics of each contact pill of an electroniccomponent having multiple contact pins used in the testing of electronicdevices, such as integrated circuit devices.

State of the Art: Generally, electronic components can be thought of ascomprising a case for housing internal circuitry and a connectingstructure for establishing electrical communication with the outsideworld—external devices such as power sources, test instruments, a secondelectronic component, or any other electronic device. A commonconnecting structure used to achieve electrical communication between anelectronic component and external devices is a contact pin. A contactpin is a metal, rod-shaped body having an external portion extendingfrom a surface of the component case and an internal portion within thecomponent case. Electrical connecting structures comprising contact pinsare well known in the art.

The external portion of the contact pin body provides a connecting pointfor establishing electrical contact between the contact pin and anexternal device. Connection to the contact pin may be temporary—forexample, by using a male-female socket connector—or connection to thecontact pin may be permanent—such as may be achieved using solder. Theinternal portion of the contact pin body may establish electricalcommunication with internal circuitry of the electronic component.Alternatively, the internal portion may extend through the componentcase and project from another surface of the electronic component,thereby establishing a second connecting point on the contact pin. Thesecond connecting point allows an external device electrically connectedto the first connecting point of the contact pin to electricallycommunicate with another external device connected to the secondconnecting point. One type of electronic component that may have such astructure is what will be referred to herein as a testsite module. Atestsite module is essentially a test bed for a second electroniccomponent. The testsite module serves as a conduit between the secondcomponent and other external devices, such as a test instrument. Also, acontact pin may provide both a connection to internal circuitry and asecond connecting point.

Although an electronic component may have only one contact pin, aplurality of contact pins is routinely necessary. For example, anelectronic component may be used in an application that requiresmulti-channel communication capabilities, thus requiring that theelectronic component have multiple contact pins. For an electroniccomponent having multiple contact pins, the contact pins are usuallyarranged in one or more two-dimensional arrays oil the surface of thecomponent case, thereby forming a pin-out. The use of hundreds ofcontact pins on electronic components is known.

During the manufacture of electronic components, the components areroutinely subjected to one or more tests to determine their electricalcharacteristics. Methods and apparatus for performing electricalcharacterization of electronic components are well known in the art. Thetype of electrical testing performed on an electronic component varieswidely, depending on the type of component being tested and individualneeds. During testing of electronic components having multiple contactpins, electrical communication between the electronic component and testinstrumentation is generally established via the contact pins. Thus, ofcritical importance in the design, manufacture, and testing ofelectronic components having a plurality of contact pins is theelectrical integrity of the pin-out itself.

A damaged or defective pin-out on an electronic component may prohibitcommunication with the electronic component during testing, or mayresult in the electronic component producing a false reading such as,for example, a false pass or fail condition. Thus, the internalcircuitry of the electronic component may be inaccurately characterized.If the electronic component is a testsite module functioning as anelectrical interface between a test instrument and a second electroniccomponent, a damaged or defective pin-out may result in inaccuratecharacterization of the second component. Characteristics that may beindicative of a damaged or defective pin-out include: a shortedcondition between an individual contact pin and any other contact pin inthe pin-out (pin-to-pin shorting), a shorted condition between anindividual contact pin and the component case (pin-to-case shorting),individual contact pin resistance that exceeds a known threshold (pinresistance), and the existence of a high-resistance connection betweenadjacent contact pins (pin-to-pin leakage).

Evaluation of pin-out integrity on electronic components such astestsite modules is conventionally performed manually by a test operatorusing a hand-held multi-meter. The conventional process requires thetest operator to measure the electrical characteristics of each contactpin, one contact pin at a time. Electronic components in the form oftestsite modules commonly have pin-outs comprised of 54 or more contactpins. When measuring pin-to-pin shorting, for example, the contact pinbeing evaluated will be checked for a shorted condition relative toevery other contact pin in the pin-out and, typically, every contact pinin the pin-out will be evaluated for pin-to-pin shorting. Thus, manualtesting can be time consuming and susceptible to human-introduced errorssuch as, for example, inaccurate measurement, non-repeatability from onecontact pin evaluation to the next, and non-repeatability from oneelectronic component evaluation to the next.

Therefore, a need exists for a method and apparatus for testing theelectrical integrity of each contact pin on an electronic componenthaving multiple contact pins. Further, a need exists for a method andapparatus for characterizing the electrical properties of a pin-out thatare accurate and repeatable. Additionally, a need exists for a methodand apparatus for characterizing contact pins that is adaptable toautomation and require minimal intervention by a test operator.

BRIEF SUMMARY OF THE INVENTION

The apparatus of the present invention is generally comprised of a testdevice, a measuring instrument, and a system controller. The test deviceis configured to hold an electronic component under test (ECUT) and toestablish electrical contact with a pin-out on the component.Simultaneous electrical contact may be established between all contactpins of the pin-out and a contact plate on the test device. If the ECUThas contact pins extending through its case to form a second connectingpoint on each contact pin, simultaneous electrical contact may beestablished with both connecting points on each contact pin using asecond contact plate on the test device.

The measuring instrument is electrically connected to the contact platessuch that electrical communication is established between the measuringinstrument and each contact pin on the ECUT. The measuring instrument isalso in electrical communication with the system controller, allowingthe system controller to direct the function of the measuringinstrument. The measuring instrument is configured to measure theelectrical characteristics of each contact pill on the ECUT that areindicative of a damaged or defective contact pin. In addition, themeasuring instrument may be configured to record and store the measuredproperties. Electrical characteristics indicative of a damaged ordefective contact pin include, but are not limited to, pin-to-pinshorting, pin-to-case shorting, pin resistance, and pin-to-pin leakage.

The system controller is configured to direct the test device andmeasuring instrument to perform at least a portion of a test sequence onthe pin-out of the ECUT. In one embodiment, the contact plates of thetest device are each associated with a positioning system adapted forcomputer control, thereby enabling the system controller to direct thetest apparatus to establish electrical communication with the ECUT. Thesystem controller may further be adapted to store and report the resultsof the test sequence.

The test sequence or method of the present invention may, by way ofexample only, include the following steps: test operator places an ECUTinto the test device; system controller directs the test device toestablish electrical contact with the contact pins of the ECUT; systemcontroller directs the measuring instrument to measure at least oneelectrical characteristic of each contact pin on the ECUT; systemcontroller directs the test device to establish electrical contact withthe second connecting point, if any, on each contact pin of the ECUT;system controller directs the measuring instrument to measure anotherelectrical characteristic of each contact pin on the ECUT; systemcontroller directs the test device to terminate electrical contact withthe ECUT; system controller directs the measuring instrument to reportthe test results to the test operator; and test operator removes theECUT from the test device. This method may then be repeated for anotherECUT.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming that which is regarded as the present invention,the features and advantages of the present invention can be more readilyascertained from the following detailed description of the inventionwhen read in conjunction with the accompanying drawings, in which:

FIG. 1 is a top view of a test apparatus according to the presentinvention;

FIG. 2 is a side vicar of the test apparatus;

FIG. 3 is a top view of an exemplary ECUT;

FIG. 4 is a front view of the exemplary ECUT;

FIG. 5 is a side view of the exemplary ECUT;

FIG. 6 is a side view of the test apparatus;

FIG. 7 is a side view of the test apparatus;

FIG. 8 is a schematic diagram of an apparatus according to thisinvention;

FIG. 9 is a flow chart of a test method according to this invention; and

FIG. 10 is a flow chart of a test method according to this invention.

DETAILED DESCRIPTION OF THE INVENTION

As illustrated, drawing FIGS. 1 through 8 contain many identicalelements, which retain the same numerical designation in all figures.

As illustrated in drawing FIGS. 1 and 2, shown is an exemplaryembodiment of a test device according to this invention. Illustrated indrawing FIG. 1 is a top view of a test device 10 while drawing FIG. 2shows a side view of the test device 10. The test device 10 includes aframe 20 having a longitudinal axis 25. Securely attached to the frame20 is a component fixture 30, which has a first side 31 and a secondside 32. The component fixture 30 is adapted to receive an electroniccomponent 100 that is to be tested (see hidden lines in drawing FIG. 2).Alternatively, the component fixture 30 may be adapted to receivemultiple electronic components 100. The component fixture 30 may haveany suitable structure capable of receiving at least one electroniccomponent 100.

Referring to drawing FIG. 1, one embodiment of the test device 10 alsoincludes a first linear positioner 60 and a second linear positioner 70.Each linear positioner 60, 70 is comprised of a rotary actuator 61, 71and a transmission mechanism 64, 74. The transmission mechanisms 64, 74convert rotary motion of the actuators 61, 71 to longitudinal motionalong an axis parallel to the longitudinal axis 25 of the frame 20.Securely affixed to the transmission mechanism 64 of the first linearpositioner 60 is a first contact plate 40. The first contact plate 40 isdisposed adjacent the first side 31 of the component fixture 30.Disposed adjacent the second side 32 of the component fixture 30 is asecond contact plate 50. The second contact plate 50 is securely affixedto the transmission mechanism 74 of the second linear positioner 70. Anysuitable structure, such as mounting brackets 44, 54, may be used toattach the first and second contact plates 40, 50 to their respectivetransmission mechanisms 64, 74.

Typically, as shown in drawing FIGS. 3 through 5, the electroniccomponent under test (ECUT) 100 is comprised of a case or substrate 110having first and second sides 111, 112, respectively. Extending from thefirst side 111 of the case 110 of the ECUT 100 is a plurality of contactpins 120. The pins 120 may be grouped together in one or moretwo-dimensional arrays to form a pin-out. The plurality of contact pins120 may also extend through the case 110 to the second side 112 of thecase 110 of the ECUT 100, thereby forming a second connecting point oneach contact pin 120. In FIGS. 4 and 5, the contact pins 120 extendingthrough the case 110 are shown in hidden line. Only a small number ofcontact pins 120 are shown extending through the case 110 for clarity;however, it should be understood that all of the contact pins 120 mayextend through the case 110 of the ECUT 100. Thus, electricalcommunication may be established with the plurality of contact pins 120on either side 111, 112 of the case 110 of the ECUT 100.

Referring to FIG. 2, the first contact plate 40 has a plurality of testcontacts 41 that is configured to electrically contact the plurality ofcontact pins 120 extending from the first side 111 of the case 110 ofthe ECUT 100. Each individual pin 120 of the ECUT 100 preferably has acorresponding test contact 41 on the first contact plate 40. Similarly,the second contact plate 50 has a plurality of test contacts 51configured to electrically contact the plurality of pins 120 on thesecond side 112 of the case 110 of the ECUT 100. Again, each individualcontact pin 120 of the ECUT 100 preferably has a corresponding testcontact 51 on the second contact plate 50. It will be appreciated bythose of ordinary skill in the art that the contact plates 40, 50 mayhave more test contacts 41, 51 than there are pins 120, thus enablingthe contact plates 40, 50 to be used in conjunction with a variety ofECUT types having differing numbers of contact pins 120. The testcontacts 41, 51 may be any suitable structure as known in the art forestablishing temporary electrical contact with a contact pin 120. Also,the contact plates 40, 50 may include additional test circuitry 59 andsensors 49 (see drawing FIG. 2) as may be necessary, depending on thetype of electrical characteristics being measured.

The first linear positioner 60 and accompanying transmission mechanism64 are configured for moving the first contact plate 40 towards thecomponent fixture 30, such that temporary electrical communication canbe established between each contact pin 120 of the ECUT 100 and acorresponding test contact 41 of the first contact plate 40. Referringto drawing FIG. 6, shown is the first contact plate 40 in an abuttingrelationship with the ECUT 100, thereby forming electrical contact withthe ECUT 100. Similarly, the second linear positioner 70 andtransmission mechanism 74 are configured for moving the second contactplate 50 towards the component fixture 30 in order to establishtemporary electrical communication between each contact pin 120 of theECUT 100 and a corresponding test contact 51 of the second contact plate50. Referring to drawing FIG. 7, shown is the second contact plate 50 aswell as the first contact plate 40, abutting and forming electricalcommunication with the ECUT 100.

The test device 10 is preferably configured such that accurate alignmentcan be achieved between the test contacts 41 and contact pins 120 andbetween the contact pins 120 and test contacts 51. Accurate contact pinalignment may be achieved by manufacturing the frame 20, the first andsecond linear positioners 60, 70, the transmission mechanisms 64, 74,the component fixture 30, and the first and second contact plates 40, 50according to tight design tolerances. Alternatively, accurate contactpin alignment may be achieved by associating a secondary adjustmentsystem 48, 58 (see drawing FIG. 2) with each contact plate 40, 50. Forexample, the secondary adjustment systems may be manually operated,two-dimensional motion stages capable of accurate positioning in twoperpendicular directions. Two-dimensional motion stages—also referred toas X-Y positioners or positioning slides—may be obtained from a numberof manufacturers such as, for example, those available from PIC Designof Middlebury, Connecticut, or Designatronics, Techno Division of NewHyde Park, New York.

As shown in drawing FIGS. 1 and 2, the frame 20 may be a generallyrectangularly-shaped structure orientated vertically with its basesurface 21 resting upon ground. If the frame 20 is in a verticalorientation, the ECUT 100 may be secured to the component fixture 30 bygravitational forces. Those of ordinary skill in the art will appreciatethat the frame 20 may be of any suitable configuration and, further,that the test device 10 and frame 20 may be orientated horizontally. Ifthe frame 20 is in a horizontal orientation, the ECUT 100 may be securedto the component fixture 30 using any suitable fastener 37 (see drawingFIG. 2) as known in the art, such as screws.

The transmission mechanisms 64, 74 may comprise any suitable devices asare known in the art for converting rotational motion to linear motion.As shown in drawing FIG. 1, and by way of example only, the transmissionmechanism 64 may include a lead screw 65 coupled with a follower 66. Thelead screw 65 is securely connected to the actuator 61 by a coupling 62,which may be either rigid or flexible. The follower 66, which issecurely connected to the first contact plate 40, is configured to movelinearly along the axis of the lead screw 65 as the lead screw 65 isrotated by the actuator 61. Therefore, rotation of the lead screw 65causes the follower 66 and attached first contact plate 40 to moveparallel to the longitudinal axis 25 of the frame 20. To provideadditional support for the first contact plate 40 while translatingalong the longitudinal axis 25, linear bearings 90 may be disposedwithin the frame 20 parallel to the longitudinal axis 25. The firstcontact plate 40 is slidably supported by the linear bearings 90.Similarly, transmission mechanism 74 also includes a lead screw 75,securely connected to the actuator 71 via coupling 72, and a follower 76coupled with the lead screw 75. The second contact plate 50 is securelyattached to the follower 76 and rotation of the lead screw 75 provideslinear motion of the second contact plate 50 along the longitudinal axis25. The second contact plate 50 is also slidably supported by the linearbearings 90. Referring to drawing FIGS. 6 and 7, shown is the first andsecond contact plates 40, 50 after being moved toward the componentfixture 30 and ECUT 100 by the first and second linear positioners 60,70, respectively.

It will be appreciated by those of ordinary skill in the art that theactuators 61, 71 may alternatively be linear actuators such as, forexample, linear solenoids. If linear actuators are used,rotary-to-linear motion conversion would not be necessary, althoughsupport features such as the linear bearings 90 may still be desirable.Those of ordinary skill in the art will also appreciate that the firstand second linear positioners 60, 70 may be manually operable. Forexample, the lead screws 65, 75 may be rotatable by a hand-operatedcrank (not shown in drawing figures). Additionally, if actuators 61, 71are used to drive the first and second linear positioners 60, 70,positioning sensors 95 (see drawing FIG. 1) may be disposed within theframe 20 and configured to sense the location of the first and secondcontact plates 40, 50, particularly as the contact plates 40, 50 come inclose proximity to the contact pins 120 of the ECUT 100.

The various parts of the test device 10 herein described may bemanufactured from any suitable materials as known in the art. The frame20, component fixture 30, and mounting brackets 44, 54 may be fabricatedfrom a metal such as, for example, 6061-T6 aluminum, or stainless steel.The lead screws 65, 75, followers 66, 76, and linear bearings 90 may bemanufactured from a suitable carbon or alloy steel. The couplings 62, 72may be fabricated from any suitable metal or plastic material as knownin the art. The design and construction of the contact plates 40, 50will vary depending on the type of ECUT 100 being tested and theelectrical characteristics being measured. Materials that may besuitable for the contact plates 40, 50 include printed circuit board,plastic, and semiconductor materials. The test contacts 41, 51 arcpreferably constructed from a suitable conductive metal as known in theart.

In order to measure the electrical characteristics of the contact pins120 on the ECUT 100, the test device 10 may be associated with ameasuring instrument 200 as shown in the schematic diagram of FIG. 8.The measuring instrument 200 is electrically connected to the testcontacts 41 of the first contact plate 40, and to the test contacts 51of the second contact plate 50. Any suitable connector cable 220 asknown in the art may be used to provide electrical communication betweenthe test contacts 41, 51 and the measuring instrument 200. The measuringinstrument 200 may be any commercially available electrical measuringdevice as known in the art, the selection of a suitable measuringinstrument 200 being limited only by the type of ECUT 100 being testedand the electrical characteristics being measured. The measuringinstrument 200 may be configured to record and store test results forlater review by a test operator.

In one embodiment, the test device 10 and measuring instrument 200 arealso associated with a system controller 300 as shown in drawing FIG. 8.The system controller 300 is in electrical communication with themeasuring instrument 200 and is configured to direct the measuringinstrument 200 to measure and record electrical characteristics of thecontact pins 120. Additionally, the system controller 300 may be inelectrical communication with the rotary actuators 61, 71, allowing thesystem controller 300 to regulate the position of the first and secondcontact plates 40, 50 with respect to the ECUT 100. Any suitableconnector cables 320 as known in the art may be used to electricallyconnect the system controller 300 to the measuring instrument 200, andto the rotary actuators 61, 71 of the first and second linearpositioners 60, 70. Thus, the system controller 300 enables the testoperator to subject an ECUT 100 to at least a partially automated testsequence. In this configuration, the test operator simply loads an ECUT100 into the component fixture 30 and directs the system controller 300to commence testing.

As part of an automated test sequence, the system controller 300 maydirect the test device 10 and measuring instrument 200 to measure asmany electrical characteristics as desired for each contact pin 120 ofthe ECUT 100. Further, the electrical characteristics of any designatednumber of contact pins 120 may be measured. The system controller 300may also be configured to record and store the test results for laterreview by the test operator. The system controller 300 may be a personalcomputer programmed by the test operator to perform a desired testsequence or, alternatively, the system controller 300 and measuringapparatus 200 may be integrated as a single, stand-alone test instrument1000 as shown in drawing FIG. 8.

A method of characterizing the contact pins 120 of an ECUT 100 using thetest device 10 and an automated test sequence will now be described.With reference to the flow chart shown in drawing FIG. 9, the testoperator first loads an ECUT 100 into the component fixture 30 of thetest device 10. The test operator then directs the system controller 300to commence testing of the ECUT 100. Next, the system controller 300directs the first linear positioner 60 to move the first contact plate40 towards the ECUT 100 until electrical communication is establishedbetween each contact pin 120 of the ECUT 100 and a corresponding testcontact 41 of the first contact plate 40.

Once electrical communication is established between the contact pins120 and test contacts 41, the system controller 300 directs themeasuring instrument 200 to measure and record a first electricalcharacteristic of each contact pin 120 of the ECUT 100. If the contactpins 120 extend through to the second side 112 of the case 110 of theECUT 100, the system controller 300 then directs the second linearpositioner 70 to move the second contact plate 50 towards the ECUT 100until electrical communication is established between each contact pin120 on the second side 112 of the case 110 of the ECUT 100 and acorresponding test contact 51 of the second contact plate 50. The systemcontroller 300 then directs the measuring instrument 200 to measure andrecord a second electrical characteristic of each pin 120 of the ECUT100.

Once the second electrical characteristic of each contact pin 120 hasbeen measured and recorded, the system controller 300 directs the firstand second linear positioners 60, 70 to retract the first and secondcontact plates 40, 50, respectively, thereby severing electrical contactwith the ECUT 100. The system controller 300 then reports the testresults to the test operator. To conclude the test sequence, the testoperator removes the ECUT 100 from the test device 10. The foregoingpartially automated test sequence can then be repeated with another ECUT100.

Attentively, as shown in the flow chart of drawing FIG. 10, theautomated test sequence may be adapted to measure an additionalelectrical characteristic. Referring to drawing FIG. 10, after thesystem controller 300 has directed the measuring instrument 200 tomeasure and record the first electrical characteristic, and prior todirecting the second contact plate 50 to make electrical contact withthe ECUT 100, the system controller 300 directs the measuring instrument200 to measure and record a third electrical characteristic of eachcontact pin 120 on the ECUT 100. Once the third electricalcharacteristic has been recorded for each contact pin 120, the testsequence continues as previously described with respect to the flowchart of drawing FIG. 9.

It will be appreciated by those of ordinary skill in the art that theabove-described method may be used to measure a wide variety ofelectrical characteristics. By way of example only, the first electricalcharacteristic may be pin-to-case shorting, the second electricalcharacteristic may be pin resistance, and the third electricalcharacteristic may be pin-to-pin shorting. Pin-to-pin leakage may alsobe measured. Those of ordinary skill in the art will also appreciatethat the automated test sequences shown in the flow charts of drawingFIGS. 9 and 10 may be significantly varied to suit the individual testoperator's needs. Also, the component fixture 30 and first and secondcontact plates 40, 50 may be configured to test more than one ECUT 100simultaneously.

In summary, the apparatus and method set forth above provide for theautomated measurement of a plurality of electrical characteristics ofeach contact pin of an electronic component having a large number ofcontact pins extending therefrom. The test method may be performedaccurately and repeatedly, and the method is easily adaptable toautomation and control by a system controller such as a personalcomputer. Automation of the test method allows for the rapid andconsistent characterization of the pin-out on a plurality of electroniccomponents with minimal intervention by a test operator and,additionally, allows for the test operator to easily vary electricalparameters measured within a test sequence by reprogramming the systemcontroller.

By way of example only, and without introducing any unnecessarylimitations therefrom, a specific application of this invention will beprovided for further illustration. The ECUT is a testsite module, whichis similar to the electronic component shown in drawing FIGS. 3 through5. The testsite module is a device used for interfacing an IC typepackage to a test instrument. The testsite module is a mechanical devicehaving many contact pins extending from two opposing sides of a modulecase for electrical connection between the IC package and testinstrument.

The test device is similar to that depicted in drawing FIGS. 1, 2, 6,and 7. The frame is a vertically orientated, rectangularly-shapedstructure. The component fixture is a mounting bracket rigidly attachedto the frame with fasteners. The testsite module is held within thecomponent fixture by the force of gravity. The first and second linearpositioners are each comprised of a Model M2INSXA-LNN-N3-02 rotarystepper motor supplied by Scientific Pacific of Rockford, Ill., and aModel 2115 lead screw and follower assembly manufactured by Rohlix andavailable from Zero-Max of Minneapolis, Minn. Linear bearings are alsomounted in the frame.

The first contact plate is a circuit board with an array of contactsconfigured to interface with the contact pins of the testsite module. Amounting bracket attaches the first contact plate to the follower of thefirst linear positioner. The second contact plate is comprised of an ICpackage and an adapter. The IC package is of the type that the testsitemodule is adapted for use with; however, all of the pins within the ICpackage are internally shorted together, creating a shorted bus. Thisshorted bus is then held within the adapter, which is supplied byAetrium Incorporated of San Diego, Calif. A mounting bracket rigidlyconnects the adapter to the follower of the second linear positioner.Both the first and second contact plates are connected to the measuringapparatus with conventional sixty conductor ribbon cables.

Alignment between the contact pins on the testsite module and the testcontacts on the first and second contact plates is achieved by tightdesign tolerances. Home position sensors are used to “home” the positionof the first and second contact plates at the beginning of a testsequence. Contact is made with the testsite module by directing thestepper motors of the first and second linear positioners to move aspecified number of steps. Stepper motors are accurate and repeatable inthis type of positioning system.

The measuring instrument is a Cirrus 1000R tester, which is anoff-the-shelf tester built by the Cirrus Systems Corporation of SaltLake City, Utah. With the first contact plate in electrical contact withthe testsite module, the Cirrus 1000R tester can test for the shortedcondition of an individual pin, and it can measure pin resistance whenboth the first and second contact plates have engaged the testsitemodule. The system controller is a personal computer capable ofinterfacing with the Cirrus 1000R tester and also includes a PC34 motorcontroller card manufactured by Oregon Micro Systems of Beaverton, Oreg.

Using the above-described apparatus, the method of characterizing thecontact pins of a testsite module comprises the following test sequence.First, a test operator loads the testsite module into the componentfixture. Second, the test operator directs the system controller tocommence testing. Third, the system controller instructs the steppermotor of the first linear positioner to move the first contact plateinto contact with the testsite module. Fourth, the system controllerdirects the Cirrus 1000R tester to check each contact pin of thetestsite module for a shorted condition with the testsite module case.Fifth, the system controller directs the Cirrus 1000R tester to checkeach contact pin of the testsite module for a shorted condition with allother pins on the testsite module. Sixth, the system controllerinstructs the stepper motor of the second linear positioner to move thesecond contact plate into contact with the testsite module. Seventh, thesystem controller directs the Cirrus 1000R tester to measure theindividual pin resistance of each contact pin of the testsite module.Eighth, the system controller directs the first and second linearpositioners to terminate contact between the first contact plate and thetestsite module and between the second contact plate and the testsitemodule. Ninth, the system controller reports the test results obtainedby the Cirrus 1000R tester to the test operator. Tenth, the testoperator removes the testsite module from the test apparatus. This testsequence can then be repeated for another testsite module.

The foregoing detailed description and accompanying drawings are onlyillustrative and not restrictive. They have been provided primarily forclearness of understanding and no unnecessary limitations are to beunderstood therefrom. Numerous modifications and alternativearrangements may be devised by those skilled in the art withoutdeparting from the spirit of the present invention and the scope of theappended claims.

1. A method of testing at least one contact pin of an electroniccomponent configured for testing electrical characteristics of at leastanother electronic component connected thereto and having a plurality oflaterally distinct contact pins through which said at least anotherelectronic component is tested when connected thereto, said methodcomprising: providing a test device for accepting said electroniccomponent; providing a measuring instrument electrically communicatingwith said test device; providing said electronic component, withouthaving any other electronic component connected thereto, having contactpins of said plurality of laterally distinct contact pins protrudingfrom both a first surface of said electronic component and a secondsurface of said electronic component; contacting at least one contactpin at a point protruding from said first surface of said electroniccomponent with said test device to establish electrical communicationbetween at least said measuring instrument and said at least one contactpin; contacting said at least one contact pin at a point protruding fromsaid second surface of said electronic component with said test deviceto establish another electrical communication between said measuringinstrument and said at least one contact pin: and measuring at least oneelectrical characteristic of said at least one contact pin with saidmeasuring instrument.
 2. The method of claim 1, wherein measuring atleast one electrical characteristic of said at least one contact pincomprises measuring a plurality of electrical characteristics of said atleast one contact pin.
 3. A method of testing at least one contact pinof an electronic component configured for testing electricalcharacteristics of at least another electronic component connectedthereto and having a plurality of laterally distinct contact pinsprotruding from both a first surface of said electronic component and asecond opposing surface of said electronic component through which saidat least another electrical component is tested when connected thereto,said method comprising: contacting at least one first contact pin ofsaid plurality of laterally distinct contact pins protruding from saidfirst surface of said electronic component with a test device;contacting at least one second contact pin of said plurality oflaterally distinct contact pins protruding from said second opposingsurface of said electronic component with said test device; providing ameasuring instrument electrically communicating with said test devicefor measuring at least one electrical characteristic of each of said atleast one first contact pin and said at least one second contact pin;and performing a test sequence measuring said at least one electricalcharacteristic of each of said at least one first contact pin and saidat least one second contact pin of said electronic component without anyother electronic component connected thereto.
 4. The method of claim 3,wherein performing said test sequence comprises: disposing saidelectronic component in said test device; making electrical contactbetween said test device and said at least one first contact pin; andmeasuring said at least one electrical characteristic of said at leastone first contact pin with said measuring instrument.
 5. The method ofclaim 4, further comprising: measuring a second electricalcharacteristic of said at least one first contact pin with saidmeasuring instrument.
 6. The method of claim 5, further comprising:making electrical contact between said test device and said at least onesecond contact pin; and measuring said at least one electricalcharacteristic of said at least one second contact pin with saidmeasuring instrument.
 7. The method of claim 4, wherein measuring saidat least one electrical characteristic includes measuring at least oneof pin-to-case shorting, pin-to-pin shorting, and individual pinresistance.
 8. The method of claim 3, further comprising: providing asystem controller electrically communicating with said test device andsaid measuring instrument; and controlling performance of at least aportion of said test sequence with said system controller.
 9. The methodof claim 3, further comprising: providing a system controllerelectrically communicating with said test device and said measuringinstrument; and controlling contact between said test device and said atleast one first contact pin with said system controller.
 10. The methodof claim 9, further comprising: controlling contact between said testdevice and said at least one second contact pin with said systemcontroller.